Fix macro expansion order in compiler_plugin_basic.swift

It looks like the extension expansion is recorded last now, it used to be the first reported extension.

Author: ahoppen

lit_tests/compiler_plugin_basic.swift

@@ -59,11 +59,6 @@ struct MyStruct {
 // CHECK-NEXT: }
 // CHECK-NEXT: ------------------------------
 
-// CHECK: @__swiftmacro_7TestApp8MyStruct9EquatablefMc_.swift
-// CHECK-NEXT: ------------------------------
-// CHECK-NEXT: extension MyStruct : Equatable  {}
-// CHECK-NEXT: ------------------------------
-
 // CHECK: @__swiftmacro_7TestApp8MyStruct8MetadatafMm_.swift
 // CHECK-NEXT: ------------------------------
 // CHECK-NEXT: static var __metadata__: [String: String] {
@@ -81,6 +76,11 @@ struct MyStruct {
 // CHECK-NEXT: @available(*, deprecated)
 // CHECK-NEXT: ------------------------------
 
+// CHECK: @__swiftmacro_7TestApp8MyStruct9EquatablefMc_.swift
+// CHECK-NEXT: ------------------------------
+// CHECK-NEXT: extension MyStruct : Equatable  {}
+// CHECK-NEXT: ------------------------------
+
 // CHECK: @__swiftmacro_7TestApp8MyStructV5value11DidSetPrintfMa_.swift
 // CHECK-NEXT: ------------------------------
 // CHECK-NEXT: {